Prosaposin ablation inactivates the MAPK and Akt signaling pathways and interferes with the development of the prostate gland

<abstract>The recent development of a prosaposin -/- mouse model has allowed the investigation of the role of prosaposin in the development of the male reproductive organs. A morphometric analysis of the male reproductive system of 37 days old mice revealed that prosaposin ablation produced a 30 % reduction in size and weight of the testes, 37 % of the epididymis, 75 % of the seminal vesicles and 60 % of the prostate glands. Light microscopy (LM) showed that smaller testis size from homozygous mutant mice was associated with reduced spermiogenesis. Both, dorsal and ventral lobules of the prostate glands were underdeveloped in the homozygous mutant. LM analysis also showed that prostatic alveoli were considerably smaller and lined by shorter epithelial cells in the homozygous mutant. Smaller tubular diameter and shorter undifferentiated epithelial cells were also observed in seminal vesicles and epididymis. In the efferent ducts of the homozygous mutant mice, the epithelium was composed exclusively of ciliated cells in contrast to the heterozygotes, which showed the presence of nonciliated cells. Radioimmunoassays demonstrated that testosterone levels were normal or higher in mice with the inactivated prosaposin gene. Immunostaining of prostate sections with an anti-androgen receptor antibody showed that the epithelial cells lining the alveoli express androgen receptor in both the heterozygous and homozygous tissue. Similarly, sections immunostained with antibodies to the phosphorylated MAPKs and Akts strongly reacted with tall prostatic secretory cells in prostate from heterozygous mouse. On the other hand, the epithelial cells in the homozygous prostate remained unstained or weakly stained. These findings demonstrate that inactivation of the prosaposin gene affected the development of the prostate gland and some components of the MAPK pathway. 63 )

Orchestration of occludins, claudins, catenins and cadherins as players involved in maintenance of the blood-epididymal barrier in animals and humans

Although spermatozoa are formed during spermatogenesis in the testis, testicular spermatozoa are immature and cannot swim or fertilize. These critical spermatozoal functions are acquired in the epididymis where a specific luminal environment is created by the blood-epididymal barrier; proteins secreted by epididymal principal cells bind to maturing spermatozoa and regulate the maturational process of the spermatozoa. In the epididymis, epithelial cell-cell interactions are mediated by adhering junctions, necessary for cell adhesion, and by tight junctions, which form the blood-epididymal barrier. The regulation of these cellular junctions is thought to represent a key determinant in the process of sperm maturation within the epididymis. Tight junctions between adjacent principal cells permit the formation of a specific microenvironment in the lumen of the epididymis that is essential for sperm maturation. Although we have made significant progress in understanding epididymal function and the blood-epididymal barrier, using animal models, there is limited information on the human epididymis. If we are to understand the normal and pathological conditions attributable to human epididymal function, we must clearly establish the physiological, cellular and molecular regulation of the human epididymis, develop tools to characterize these functions and develop clinical strategies that will use epididymal functions to improve treatment of infertility. （Asian J Androl 2007 July; 9： 463- 475）

Nutritional modulation of the inflammatory response in inflammatory bowel disease-From the molecular to the integrative to the clinical

Nutrient deficiencies are common in patients with inflammatory bowel disease (IBD). Both total parenteral and enteral nutrition provide important supportive therapy for IBD patients, but in adults these are not useful for primary therapy. Dietary intervention with omega-3 polyunsaturated fatty acids contained in fish oil may be useful for the care of IBD patients, and recent studies have stressed the role of PPAR on NFκB activity on the potential beneficial effect of dietary lipids on intestinal function.

AB040.Pou2f1/2 are required for the specification of cone photoreceptors in the developing retina

Background:Rods and cones are critical for light detection.Although there has been considerable work done in elucidating the molecular mechanisms involved in rod development,not much is known about how the cone cell fate decision is made by the multipotent retinal progenitor cells during development.Analysis of the promoter regions of Nrl and trβ2,rod and cone differentiation factors respectively,revealed DNA binding motifs of two POU-domain containing transcription factors,Pou2f1 and Pou2f2.Preliminary experiments showed that Pou2f1/2 are expressed during the peak of cone genesis in the embryonic retina.Therefore,we hypothesize that Pou2f1/2 specify cone cell fate in the developing retina.Methods:We used immunofluorescence and in situ hybridization to establish the spatiotemporal expression of Pou2f1/2 during retinogenesis.We performed in vivo electroporation in post-natal mice to misexpress Pou2f1/2 and used antibodies specific to proteins expressed in cones such as Rxrγand S-opsin to count cones.Using ex vivo electroporation of embryonic retinal explants,we knocked out Pou2f1 and Pou2f2 using CRISPR/Cas9 gRNAs at the peak of cone production window.Finally,we transfected post-natal retinal explants with a combination of regulatory elements of Nrl or thrb with control backbone vector,Pou2f1 or Pou2f2 using electroporation.Results:We found that Pou2f1/2 are expressed in retinal progenitor cells in the developing retina and subsequently in the differentiated cones.Pou2f1/2 misexpression outside the cone genesis window led to an increase in cones at the expense of rods.Pou2f1/2 indel knockouts generated by CRISPR/Cas9 gRNAs led to a decrease in cones and a converse increase in rods.Finally,we found that Pou2f1/2 activate the cis-regulatory module(CRM)of the thrb gene and repress the activity of the CRM of Nrl.Conclusions:These results uncover novel players that establish the complex gene regulatory network for cone photoreceptor fate specification in the retinal progenitor cells.We anticipate that this work should help us devise improved replacement therapies in the future utilizing stem cells for retinal degenerative diseases such as aged-related macular degeneration(AMD)and Stargardt’s disease.

Physiological evidence of integrin-antibody reactive proteins influencing the innate cellular immune responses of larval Galleria mellonella hemocytes

Larval Galleria melonella(L.)hemocytes form microaggregates in response to stimulation by Gram-positive bacteria Hemocyte adhesion to foreign materials is mediated by the CAMP/protein kinase A pathway and the B-subunit of cholera toxin using a cAMP-independent mechanism.Cholera toxin-induced microaggregation was inhibited by the integrin inhibitory RGDS peptide,implying integrins may be part of the mechanism.Based on the types of mammalian integrin-antibody reactive proteins affecting hemocyte adhesion and bacterial-induced responses ars,ory,Ai,and B3 subunits occred on both granular cell and plasmatocyte hemocyte subtypes.A fluorescent band representing the binding of rabbit as-integrin subunit antibodies occurred between adhering heterotypic hemocytes.The frequency of the bands was increased by cholera toxin.The as andβrabbit integrin subunit antibodies inhibited removal of Bacillus subtilis(Cohn)from the hemolymph in vivo,A as ir-specific synthetic peptide blocker similarly diminished hemocyte function whereas the 0v Bs-specific inhibitory peptide and the corresponding integrin subunit antibodies did not influence nonself hemocyte activities.Western blots revealed several proteins reacting with a given integrin-antibody subtype.Thus integrin-antibody reactive proteins(which may include integrins)with possible as and B epitopes modulate immediate hemocyte function.Confocal microscopy established plasmatocyte adhesion to and rosetting over substrata followved by granular cell microaggregate adhesion to plasmatocytes during early stage nodulation.

The Vision Health Research Network Annual Research Day

The Vision Health Research Network(VHRN)was established in 1995 to increase research capacity,productivity,and visibility of vision science carried out in Quebec,Canada.The VHRN is funded by the Fonds de la recherche du Québec en santé(FRQS),a Quebec government agency,and the Foundation Antoine-Turmel,a private charity organization.In the past decades,the VHRN has fostered productive collaborations and helped improve access to specialized infrastructure and tissue banks,thereby enhancing competitivity of Quebec vision research on the international stage.The VHRN also supports vision research directly by providing seed funding for national and international collaborative projects.The VHRN is also dedicated to support the training of the next generation of vision researchers by funding scholarships and awards for the best trainees,which not only help them carry out their projects but also make them more competitive to apply for funding at national and international granting agencies.The VHRN strongly believe that these research building initiatives will help us achieve our ultimate goal,which is to improve care and develop treatments for patients living with various vision impairments.

Anti-cancer liposomal chemophototherapy using bilayer-localized photosensitizer and cabazitaxel

Photodynamic therapy(PDT)is a non-invasive tumor ablation modality that can be enhanced in combination with concurrent chemotherapy.Previously,we demonstrated that liposomes containing a bilayer-anchored photosensitizer(porphyrin-phospholipid;PoP)can be loaded with drugs in their aqueous core to improve drug delivery and tumor ablation upon target tissue irradiation with red-light.In the present work,we demonstrate that this concept can be extended to drugs loaded within the hydrophobic bilayer of liposomes.Cabazitaxel(CTX)is a potent second generation taxane anti-cancer drug that was loaded in the bilayer of liposomes also containing 0.1 molar%PoP,generating CTX-loaded PoP liposomes(CTX-PoP-Lip).CTX-PoP-Lip showed unilamellar vesicle morphology,and exhibited integrity in storage and serum,while maintaining drug stability under laser irradiation.In vitro cell killing evaluation showed that red-light laser irradiation induced cytotoxicity in cells incubated with CTX-PoP-Lip,compared to control treatments.In vivo pharmacokinetic analysis revealed that following intravenous administration to mice,CTX and PoP exhibited somewhat altered circulation profiles,suggesting that the CTX may have exchanged with serum factors in blood.Nevertheless,when a single treatment of CTX-PoP-Lip with laser irradiation was administered to mice bearing human MIA Paca-2 tumors,tumors were effectively ablated whereas the equivalent chemotherapy and PDT monotherapies were ineffective.These results demonstrate the versatility of liposome delivery systems for achieving tumor ablation with chemophototherapy.

Relatively rapid evolution rates of SARS-CoV-2 spike gene at the primary stage of massive vaccination

A series of stringent non-pharmacological and pharmacological interventions were implemented to contain the pandemic but the pandemic continues.Moreover,vaccination breakthrough infection and reinfection in convalescent coronavirus disease 2019(COVID-19)cases have been reported.Further,severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)variants emerged with mutations in spike(S)gene,the target of most current vaccines.Importantly,the mutations exhibit a trend of immune escape from the vaccination.Herein the scientific question that if the vaccination drives genetic or antigenic drifts of SARS-CoV-2 remains elusive.We performed correlation analyses to uncover the impacts of wide vaccination on epidemiological characteristics of COVID-19.In addition,we investigated the evolutionary dynamics and genetic diversity of SARS-CoV-2 under immune pressure by utilizing the Bayesian phylodynamic inferences and the lineage entropy calculation respectively.We found that vaccination coverage was negatively related to the infections,severe cases,and deaths of COVID-19 respectively.With the increasing vaccination coverage,the lineage diversity of SARS-CoV-2 dampened,but the rapid mutation rates of the S gene were identified,and the vaccination could be one of the explanations for driving mutations in S gene.Moreover,new epidemics resurged in several countries with high vaccination coverage,questioning their current pandemic control strategies.Hence,integrated vaccination and non-pharmacological interventions are critical to control the pandemic.Furthermore,novel vaccine preparation should enhance its capabilities to curb both disease severity and infection possibility.